During the processing of chickens, turkeys, and other poultry in a poultry processing plant which defeathers, eviscerates, cuts up, and packages the poultry for delivery and sale, it is highly desirable to perform as many of the processing steps as possible using automated machinery and processes. The use of automated machinery minimizes the more expensive manual handling of poultry carcasses as well as provides for more uniform cutting of the poultry carcasses.
In recent years during automated processing, poultry carcasses have been suspended by their legs from a suspended "overhead" conveyor system, and many of the processing steps have been automatically performed on the poultry carcasses as they are moved in series along the overhead conveyor system. For example, now in the industry, poultry carcasses can be defeathered, decapitated, opened, and eviscerated while being advanced progressively through a poultry processing plant on the overhead conveyor system. It is further desired that the poultry carcasses be segmented, or cut up, via automated processes while continuing their travel on the overhead conveyor system, so as to avoid the manual handling of the poultry carcasses when performing the hazardous and time-consuming cutting functions. Examples of such automated on-line cut-up operations are shown and described in U.S. Pat. No. 5,147,240 to Hazenbroek et al., U.S. Pat. No. 5,015,213 to Hazenbroek et al., and U.S. Pat. No. 5,035,673 to Hazenbroek et al., all of the disclosures of which are incorporated herein by reference. However, despite the achievements set forth in the foregoing patents, it is still a common practice in the industry to remove the poultry carcasses from the overhead conveyor system in order to perform cut-up operations on the poultry carcasses.
A significant problem with cutting apart poultry carcasses as the poultry carcasses are carried by the overhead conveyor system has been that it is difficult to make clean and accurate cuts through the center of the keel bone. In a poultry carcass, the keel bone resides in the front in opposing relationship to the vertebrae. The keel bone is analogous to the sternum in humans. Ribs connect between the vertebrae in the rear and the keel bone in the front. Further, from compositional vantage point, the keel bone is essentially a combination of bone tissue near the top and cartilage tissue near the bottom, making the keel bone somewhat flexible and movable, and therefore difficult to cut in the center.
Oftentimes, when the keel bone is cut, the keel bone is cut off center so that two disproportionate breasts result from the cutting process. Needless to say, vendors of breast products do not want to sell nonuniform breast products to consumers. In addition to the nonuniformity problem, one or both of the resulting breasts may have muscle tissue unattached to a rigid cut edge. Essentially, the dangling muscle tissue comprises a major pectoral muscle and a minor pectoral muscle separated via a cavity. Moreover, during marination of the breast having the dangling muscle tissue, the major and minor pectoral muscles undesirably separate, thereby making the marination process awkward and making the marinated breast aesthetically unpleasing. Furthermore, marination spices, such as hot spices, often get lodged and accumulate within the cavity separating the major and minor pectoral muscles. This accumulation can drastically distort the taste of the marinated breast and can potentially cause injury.